Rock-drill.



E. M. MACKIE & P. F. DOYLE.

ROCK DRILL. APPLICATION rILBD JAN. 19, i909.

Patented Dec. 9, 1913.

2 SHEETS-SHEET l.

l i In E. M. MACKIE 6L P. F. DOYLE.

ROCK DRILL. APPLICATION FILED-JAN. 19, 1909.

Patented Dec. 9, 1913.

Mdm@ (5565,'

v UNITED STATES PATENT OFFICE.

EDWIN M. MACKIE AND PERCIVAL F. DOYLE, OF FRANKLIN, PENNSYLVANIA,`ASSIG'NORS T0 CHICAGO PNEUMATIC TOOL COMPANY, OF CHICAGO, ILLINOIS,

A CORPORATION OF NEW JERSEY.

ROCK-DRILL.

Specification of Letters Patent.

Patented Dec.9, 1913.

To all 'whom it may concern Be it known that we, EDWIN M. MACKIE andPEnorvAL F. DoYLE, both residing at Franklin, Venango county,Pennsylvania, the former'beinga citizen of the United States and thelatter a citizen of the Dominion of Canada, have invented certain newand useful Improvements in Rock-Drills, of which the following is aspecification.

Our invention relates to rock drills, more particularly those of thetype known as hammer drills, and the object thereof isI to rovide adrill with an air feed device havlng a novel and reliable constructionof governor capable of regulating the degree of pressure admitted to theair feed device so that any predetermined amount or any amount less thanthe working pressure of the drill may be employed for such device andalso to provide a Y overnor of this character with means for re easingthe pressure or motive Huid so admitted.

Other novel 4and advantageous features of construction and operationwill be apparent from the description hereinafter given. 'y

In the drawings, Figure 1 is-a plan view of our improved rock drill withan air feed device attached thereto; Fig. 2 a side v iew of the rockdrill `or machine showing the rock drill proper in section and the `airfeed device partly 1n section; Figs. 3, 4,'5 and 6 are sections on the`lines 3 3, 4 4, 5 5 and 6 6 vrespectvel of Fig. 2, but on a somewhatlarger sca e; Fig. 7 a section on the line 6 6 of Fig. 2; Fi a sectionon the line 8 8 of Fi 9; an Fig. 9 a section on the line 9 9 of 'ig. 1or a section on line 9 9 of Fig. 8.

Referring' to vthe resent embodiment of our invention, the' e ements ofthe hammer are of the usual construction, so that it will sutlice torefer to same in general terms. As shown in Filg. 2, the hammer piston 1reciprocates in t e c linder 2 to which the fluid pressure is a mittedand released by means of the valve 3 workin in coperation withthe iston1, with t e .result that the piston wil be reciprocated in opposite'directions and caused to deliver its blow on its forward stroke. Thevalve vis adapted to operate in a suitable valve box or bushing 4,7whosefront end is closed from the cylinder or piston chamber by means of thevalve box cap 5. The cylinder is provided with a back head 6 having itsforward end formed as a socket whose upper or inner end 7 is adapted tocontain the valve box 4 and whose lower or outer end 8 is adapted toyreceive the rearward end 9 of the cylinder. This end of the cylinder,as well as the inner diameter of the outer -end of the back head socket,are suitably machined so as to slip freely upon each other, the lengthof fit being sufficiently long to reserve aline-- ment of cylinder 2 andthe ead 6 so that the endv surface 10 of the socket will cbme true withthe end surface 11 of the valve box. This fitting of the baci head andcylinder provides a slip joint and the parts are clamped together by thesame clampingy means which clampvthe front head to the cylinder ashereinafter described.

The back head 6 is provided with a rear- `ward extension 12 in which isadapted to fit the forward end ofthe hollow feed piston 13 of the airfeed device.V The extension 12 is slotted at its upper end as indicatedin Figs. 1 and 2, in order to act as a clampin connection with theclamping bolt 14, whereb7 upon tightenin such bolt the described partswhich thus ave a slip joint connection are secured together. Asindicated in detail in Fig. 5, the clamping bolt 14 is so` positionedthat it lies 1n a groove formed on one side of the feed piston 13, withvthe result that such piston is locked in place and prevented fromrotatin escribing the air feed device, the same comprises the feedbarrel 15 and the center piece 16 which closes the upper end of sucharrel. The hollow feed plston 13 is provided with Huid pressureconnections and in the present instance with a iiuid lpressure governoror re ulator for such pressure now to be describef.

The back head 6 is provided with a fluid pressure passage 17 whichsupplies the fluid pressure to the o erating parts of the drill when thethrott e valve 1s opened. yThis throttle valve consists in the presentinstance of a three-way valve 18 of the plug type, with a centralpassage 19 communlcating withk a suitable source of fluid pressuresupply, as indicated in Fig. 1. The valve is rovided with an operatinghandle 2O w ich when moved in an anti-clockwise direction,

ton 26 having a central passage 27 and radial passages 28. This pistonis held in normal position with a yielding pressure which,

1n the present instance, conslsts of a spring 29 exerting its influenceupwardly against the piston 26 through themedium of the sleeve 30movable asa piston in the lower and enlarged diameterv of the casing 25.The tension of this spring is adjustable -by hand by means of theadjusting nut 31 which, when screwed in one direction or the otherregulates the tensionof such spring. When the Huid pressure is admittedto the governor as hereinbefore described it will tend to force thepiston 26 downwardly and if such pressure exceeds the force of thespring, such pistonI will be moved downwardly with the resultl that thefluid pressurewill be admitted through 27 and 28 to the cross passages32and 33 and into the longitudinal chamber 34 in the interior of the feedpiston 13. The fluid r for the efficient working of t pressure nowfilling this chamber 34 will act upon the surface 35 of the rearward endo the feed barrel l5 and will force the feed piston away from such enduntil the drill steel is brought up against the material to be drilled.

It is desirable to regulate the degree of pressure admitted tothe air.,feed devlce and particularly to maintain the same at any desired ressureless than the workin pressurel, t atV is the fluid pressure operatingthe dril This is an im ortant feature, inasmuch as it has been frdund inractice that lire drill the same should be held or forced more firmlyagainst the formation being drilled when it is hard, like granite, thanagainst a soft formation like sandstone. Inpractice, in order to obtainthe desired pressure in the chamber 34 of the air feed device, theadjusting screw or cap 31 being screwed inwardly to its full extent togive the spring 29 its maximum tension, the valve 18 is operated toadmit air to the governor and thereupon the adjusting screw 31 is slowlyunscrewed or backed off, thereby lessenin the resistance of the spring29 until the uid pressure in the chamber 34 is at the required de ree,which will be less than the pressure o the Huid entering the` governorto an amount equal to the resistance of the spring 29.

After the air feed pressure has been estabthe passages y when in saidnormal posltion with a passage 18 in the body of the valve, which latterpassage communicates with the supply passage 22 hereinbefore described.When the governor is thus released of pressure the spring 29 will returnthe parts, including the piston 26, to normal position, as shown in Fig.7, whereupon the pressure from the chamber 34 will escape throughpassages 32 and 33, thence through passage26 and port 26", as indicatedby the arrows in Fig. 7.

When the drill is to be used without the air feed device the clampingbolt 14 is removed and the feed piston is withdrawn from the extension12 of the back head and the air feed device is replaced by another piecesuitable for the work to be done. Also the pipe connection 23 isdisconnected from the valve and a suitable plug inserted in the opening22.

The front head of the drillis adapted to be secured to the cylinder by aslip joint in the same general manner as the back head and to this endsuch a front head 36 is suitably machined on its upper end to form acapfor the lower end of the drill cylinder. This head, as well as theback head, is rigidly held in position by means of the tie rods or bolts37 which serve to clamp such headsto each other and to the interposedcylinder. The interior of the upper end of the lower or front head isprovided with a two diameter bore in order to receive the striking piece37 which lis of corresponding two diameters. This striking piece isarranged to receive the blow of the hammering piston 1 and to transmitthe same to the inner end of the drill steel 38 which is inserted in thefront end of the front bushing 36 and received by the chuck bushing 39.In' order lto facilitate the-removal of the chuck bushing the front headis slotted` as seen in Figs. 1 and 2 and provided with a clamping bolt4Q for clamping such head upon the bushing. This clamping bolt isadapted to lie in a depression formed on one side of the bushing, so astofprevent the latter from rotating. This\front head forms a water headand to this end the same is provided with 'a water supply passage 41arranged to communicate with a water supply passage 42 extendinglongitudinally of the drill cylinder, the same being connected to anysuitable source of water or both air and water controlled by suitablevalve mechanism 43. In order to provide for a proper connection betweenthe passages 41 and 42 and also to locate or determine thel properrelative position of the front head and the cylinder, we provide ahollow dowel 44 located at the joint between the front head andcylinder. The water assage 41 communicates with the bore of3 the fronthead at the shoulder formed between the two diameters of the bore andthe water so admitted is adapted to flow through radial passages 45 inthe striking piece 37', which passages communicate with a common centralpassage 46. This passage in turn is arranged to communicate with acentral passage 47 in the drill steel. In order to prevent leakage ofthe fluid around the striking piece the same is provided with suitablepacking 48, preferably leather, and likewise for the same purpose thedrill steel is provided with suitable packing 49 arranged behind thechuck bushing 39 and around the inner end of the drill steel. Under thisconstruction and arrangement the water or air land water mixed may beadmitted through the passages 42 and 41, thence through the. passages 45and 46 in the striking piece, and finally through the passage 47 in thedrill steel to the cutting end of the latter, thereby obtaining in anovel and simple manner all of the advantages recited in the preamble ofthis specification. By the provision of the governor for the air feeddevice a predetermined degree of pressure may be provided for suchdevice and maintained thereat according to the strength or firmness ofthe formation being operated upon. Furthermore, by reason of theso-called slip joint connections we are enabled to eliminate threadedconnections 'between the heads and the cylinder and also between the airfeed and the cylinder, which threaded connections are very undesirableand a source of considerable trouble on account of the threads becomingdry and rusty and making it difficult to unscrew one member from theother after the drill has been in service even for a short time.

We claim:

1. In combination with a rock drill, an air feed device cooperatingtherewith, a valve for admitting pressure fluid to the air feed, and afluid pressure actuated governor for controlling the degree of pressureadmitted tosuch device, said governor having provision for releasingsuch pressure therefrom.

2. In combination with a rock drill, an air feed device cooperatingtherewith, a

valve for admitting pressure fluid to thedrill and to the air feeddevice, and a fluidpressure actuated governor interposed between suchvalve and said device for controllmg the degree of pressure admitted tosuch device, said governor havin provision for releasing such pressurethere rom.

8. In a rock drill, the combination with a motive fluid operated motorand motive fluid operated feedingV meanstherefor, of means fordelivering motive fluid under pressure to the motor and to the feedingmeans, and mechanism for varying the p sure of the motive fluiddelivered to the eeding means relative to that delivered to the motor,said mechanism having provision for releasing such motive fluidthenefrom.

4. In a rock drill, the combination with a motive fluid operated motorand motive fluid operated feeding means therefor, of means fordelivering motive fluid under pressure to the motor' and to the feedingmeans, and mechanism for varying the pressure of the motive fluiddelivered to the feeding means Without affecting the pressure of thefluid delivered to the motor, said mechanism having provision forreleasing the motive fluid delivered to the feeding means.

5. In a rock drill, the combination with a motive fluid operated motorand motive fluid operated feeding means therefor, of a supply conduithaving branches leading respectively to the motor and to the feedingmeans, and variable pressure reducing means located in the branch thatleads to the feeding means, said means having provision for releasingthe motive fluid delivered to the feeding means. Y

6. In a rock drill, the combination with a motive fluid o rated motor,of motive fluid operated fee ing means therefor, means for deliveringmotive fluid to the motor and feeding means, including.separate channelsleading thereto, and variable pressure-reducing mechanism controllingthe passage of motive fluid through one of said channels, said mechanismhavin provision for releasing the motive fluid livered to the feedingmeans.

7. In combination with a rock drill, an air feed device cooperatingtherewith, a valve for supplying the pressure fluid admitted' to the airfeed device, and a fluid pressure actuated governor interposed betweensuch valve and said device for admitting the pressure fluid to thelatter and its release therefrom, such governor comprising a casing withports communicating respectively with the feed device, with theatmosphere and with the supply from said valve, a piston controlling thefirst two mentioned ports, and means operating upon the piston to causeit to resist 'the 'pressure fluid admitted to the governor by the valve.

8. In combination-with a rock drill, an air feed device cooperatingtherewith, a valve for supplying the pressure fluid admitted to the airfeed device, and a fluid pressure actuated governor interposed be- CFItween such valve'and said device for admitting the ressure fluid to thelatter and its release t erefrom, such governor compris- .ing a casingwith ports communicating respectively with the feed device, with theatmosphere and with the supply from said valve, a piston controlling thefirst two mentioned ports, a sleeve movable in said casing and adaptedto bear against the piston, and a spring cooperating with said sleeve.

9. In combination with a rock drill, an air feed device cooperatingtherewith, a valve for supplying the pressure fluid admitted to the airfeed device, and a fluid pressure actuated governor interposed betweensuch valve and said device for admitting the pressure Huid to the latterand its release therefrom, such governor comprising a casing with portscommunicating respectively with the feed device, with the atmosphere andwith the supply from said valve, a piston controlling the first twomentioned ports, a sleeve movable in said casing and adapted to bearagainst the piston, an adjustable screw plug screwing into said casing,and a sprlng interposed between the sleeve and the plug.

10. In combination with a rock drill, an air feed device coperatingtherewith, a valve for supplyin the pressure fluid admitted to the airfeed device, and a fluid pressure actuated governor interposed betweensuch valve and said device for admitting the pressure fluid to thelatter and its release therefrom, such governor comprising a casing withcommunication respectively with the valve, feed device and atmosphere, apiston movable within the casing and having ports 28 adapted to registerwith the feed device communication, said piston being arranged to governthe communication to atmosphere and the casing having a passage 26"*adapted to communicate between the feed device and the communicationwith atmosphere when not closed by the piston.

11. In combination with a rock drill, an air feed device coperatingtherewith, a valve for admitting pressure fluid to the air feed device,and a fluid pressure actuated governor interposed between such valve andsaid device for controlling the degree of pressure admitted to suchdevice, said valve having means for releasing the pressure admitted tothe governor and acting upon the latter.

12. In combination with a rock drill, an air feed device coperatingtherewith, a valve for admitting pressure fluid to the air feed device,and a fluid pressure actuated governor interposed between such valve andsaid device for controlling the degree of pressure admitted to suchdevice, said valve being adapted to release the pressure admitted to thegovernor, and having a way connecting between the governor and a sourceof motive fluid supply for the admission of motive fluid to the governorand having a second way connecting between the governor and theatmosphere when the first mentioned way is closed for releasing themotive fluid acting upon the governor.

13. In combination with a rock drill, an air feed device coperatingtherewith, a valve for supplying the pressure fluid admitted to the airfeed device, a fluid pressure actuated governor interposed between suchvalve and said device for admitting the pressure fluid to the latter andits release therefrom, such governor including a casing having ports andpassages communieating respectively with the valve, feed device andatmosphere, and a piston movable in the casing for governing said portsand passages, said piston being normally in a position of release butcapable of positions of admission and of lap, said valve having meansfor releasing the pressure upon the piston to permit the latter toreturn to normal position.

14. In combination with a rock drill, an air feed device coperatingtherewith, a valve for supplying the pressure fluid admitted to the airfeed device, a fluid pressure actuated governor interposed between suchvalve and said device for admitting the pressure fluid to the latter andits release therefrom, such governor including a casing having ports andpassages communicating respectively with the valve, feed device andatmosphere, and a piston movable in the casing for governing said portsand passages, said piston being normally held 1n a posit-ion of releaseby an adjustable spring pressure but capable of positions of admissionand of lap, said valve'having means for releasing the pressure upon thepiston to permit the latter to return to normal position.

15. In combination with a rock drill, an air feed device cooperatingtherewith, a valve for admitting pressure fluid both to the drill and tothe air feed device, and a fluid pressure actuated governor interposedbetween such valve and said device for controlling the degree ofpressure admitted to such device, said valve having means for releasingthe pressure admitted to the governor and acting upon the latter.

EDWIN. M. MACKIE. PERCIVAL F. DOYLE.

Witnesses GRACE T. HoPKINs, J. B. WILLIAMS.

